Your mum gay is the ultimate response to when someone is being annoying or is getting angry with you.

You can add the "lol" at the end to give it that extra punch.

Your mum gay was also used by Pewdiepie in February 2018. But it was originally created by NFKRZ Bangerz in a Pyrocinical video when in a CS:GO match when someone said "Why did you do that" and he replied with "Because your mum gay" and after a eruption of laughter happened.
It has also been a running joke on NFKRZ's channel as he is also Russian and mocking people who can't speak English that well.